I recently started a project to build a 10W LED light for a saltwater fish tank. I ended up using 8 1.2W Avago LEDs, 2 6500K White, 2 470nm Blue and 4 455nm Royal Blue. Each LED has a vf of 3.2v@.350mA. Power supply is 7.5v@1.8A.



First step was to draw out my circuit, I used photoshop to do it, but mspaint would probably work fine. Here is a picture of the circuit.





Now I used a razor and cut out all the black parts of the now stencil. using the stencil I traced the circuit onto a 6x9 piece of copper clad board using a etch resist pen.





In the etching tub, cut to size. I used Ferric Chloride to etch off the excess copper.





This is right out of the etch, rinsed and mineral spirits to get rid of the ink. (eww weird oxidation)





Finished product, ready for component placement and soldering. (This was not the board I used in the final product, but it's the only one I have a picture of at this stage)





Now I need to make the heat sink. I used 3/4x1/8 aluminum strip and cut it into 3.5 pieces, I cut the base from a 2x1/8 strip. then I bent 2 pieces to form the switch box. Assemble the switch on the plate and Im ready to assemble.





It was all put together with Arctic Silver thermal Adhesive, assembly is pretty straight forward, add glue hold in place, let dry.





Now on to attaching my lights. First I tinned all the solder pads. I used the same thermal adhesive as I did for the heatsink and glued the metal slug down to the PCB. After letting the adhesive dry for about 30 mins. I applied heat and a touch more solder to connect the leads to the PCB.





Lets see how bright this sucker is!





Ok, looks like everything is working so it's time to assemble. I glued the PCB to the heatsink, again giving it time to dry. I drilled a hole through the board and heatsink to the switch and added wires to the +- terminals.





Switch wired in and silicone applied to all connections, then taped





Lens installed with silicone, sealing in the circuit to protect it from moisture. I had the lens made at eplastics.com





Finally fully assembled and on, first picture is with a florescent light overhead and the second is in the dark.









I'll have a couple more pics coming when I install the light on the tank.